Heating System

With the Ignition Switch in RUN and the Heater Control Assembly in any position except, OFF, voltage is applied to the Blower Motor. With the Blower Motor switch in LO, current flows through the Blower Motor and three resistors. IN MED-LO, current flows through two resistors. In MED-HI, current flows through one resistor. In Hi, current does not flow through a resistor. With the A/C-Heater Function Selector Switch in OFF, the Blower Motor does not run.

Lever Position and Operation

OFF

Vacuum is applied to the Outside-Recirculate Door Vacuum Motor, closing that door to outside air. The Panel Door closes the instrument panel outlets. The Floor-Defrost Door opens the floor outlets. The Blower does not operate and air does not pass through the system.

VENT

Outside air comes through the Outside-Recirculate Air Door. The Panel Door sends air to the instrument panel outlets (vacuum on motor). The Temperature Blend Door controls the air through the Heater Core.

FLOOR

Outside air controlled by the Temperature Control Lever passes through or around the Heater Core. The Panel Door closes and air is sent to the floor outlets (vacuum at ports A and B of the Floor-Defrost Door Vacuum Motor).

FLR/DEF

The Outside-Recirculate Air Door lets in outside air (no vacuum at motor). Vacuum is applied to port A of the Floor-Defrost Door. The door moves to mid-position and air is split between the floor and defrost outlets. The Panel Door closes.

DEFROST

With no vacuum at any Vacuum Motor, air passes through the outlets.